Electrical device



Oet.V 26, 1937. n M. PIRANl 2,097,303.

ELECTRICAL DEVICE Filed Aug. 4. 193?- [NT/ENTDA WAUE'LLD Ffwf E. mf MM TTDHNE'Y' Patented Oct. 26, 1937 j UNITEDy STATES 2,091,303 montreal. mmol:

Marcello Pirani, Berlin-Wilmersdorf, Germany, assignorto General Electric Company, a corporation of New York Application August 4, 1933, Serial No. 883,710

In Germany August 18,1932

'I Claims. l (Cl. 240-13) My invention relates to electrical devices for emitting light of high intensity for use, for instance, in photography, and is especially adaptable to thatclass of devices in which the light is produced by passing a high electric current through a iilamentary wire, even to the point of vaporlzation. This device may be used in the so-called photofiash lamps.

According to my invention, the fllamentary wire is mounted on an insert comprising an insulating block which is provided with terminal o onnections for insertion in a holder or housing, so that it may be readily removed and another Awire placed therein. The insert is preferablyin ul5 the form of a plate or-frame with two opposite projecting edges. The wire is supported by the projecting edges and extends to contact stripson the back of the plate. One of the advantages of such inserts is their ready interchangeability in the samehousingor projector. A supply of insorts may be kept on hand and renewed simply by inserting a new wire therein. Another advantage is the construction of the projecting edges which serve to prevent arcing at the connections when the lament burns through, thus preventing a fusion of the connections. Further features and advantages of my invention will appear from the following detailed description of species thereof and from the drawing.

In the drawing, Fig. 1 is an elevation, partly in section, of the holder or projector; Fig. 2 is a plan view of the insert; Figs. 3 and -4 are front and side views thereof; and Fig. 5 is a side view of an insert with a modified form of terminal connection.

Referring to Fig. 1, the projector consists of a cylindrical housing Il having a reflector il mounted at the forward end thereof. I'he housing Il is mounted on a support arm I3 by la bracket I4. A socket I5 is located in the forward' end of housing j I and is connected to current supply wires IS. A switch l1 is also provided in the housing It.

`Referring to Figs 2 to 4, the insert comprises a plate 'Il of insulating material such as asbestos shale, steatite magnesia, soapstone or similar material. Said plate I8 carries terminal connections comprising a screw-threaded base i9 auch as is commonly used on incandescent lamps, or a pair .50 of split pins 20, one of which is shown in Big5. Two opposite edges 2l, 22 of the plate I8,- are made heavier or project forwardly of the surface of the plate and are provided with grooves 23. A pair of contact strips 24, 25 are provided on 55 the bock of plate II, the ends 2l, 2l Projecting through holes in said plate l8 and being bent over to clamp said stripsto said plate. The said contact plates 24, 25 are provided with upstandl ing lugs 28, 29 formed therefrom. The light producing means comprises a nlamentary wire Il, 5 which may be of tungsten, and is strung between the lugs 28, 29, portions thereof lying in the grooves 23 in the projecting edges 2l, 22. The wire is thus disposed in parallel Arows across the .face of plate I8 as shown in Figi 2, the rows being l0 25 and the ends of the lament. When a momentary flash of light of high intensity is desired, 2o the filament is of course designed for a sumciently low voltage so that it will be almost instantaneously vaporized. What I claim as new and desire to secure by Letters Patent of the United States, is: 1. An electrical device for emitting light consisting of an interchangeable insert comprising an insulating plate having a pair of oppositely disposed projecting edges, a terminal connection member mounted thereon, aV pair of contacts on 30 said plate, and a fllamentary wire having the ends thereof connected to said contacts and passing over said projecting edges.

2. An electrical device for emitting light consisting of 'an interchangeable insert comprising 35 an insulating plate having a pair of oppositely disposed projecting edges, a terminal connection member mounted thereon, a pair of contacts mounted on the back of said plate and having a plurality of upstanding lugs thereon, and a nia- 40 mentary wire wound around said lugs and across said edges in a plurality of rows.

3. An electrical device for emitting light consisting of an interchangeable insert comprising an insulating plate havinga pair ofoppositely 45 disposed projecting edges having grooves therein,

a terminal connection member mounted thereon, a pair of contacts on said plate, and a filamentary wire having vthe ends thereof connected to said contacts and passing over said projecting edges through the grooves therein.

4. An electrical device adapted for photographic and other uses requiring high light` intensity and consisting of an interchangeable plug comprising an insulating plate carrying terminal connection 56 members, contacts carried by said plate and electrically connected with said terminal connection members, and a'lament extending across the face of said insulating plate and designed so that uponr'receiving avery high electric current it is instantaneously vaporized and emits light of hi'gh intensity, said lament having electrical coni nection with said contacts without being integrally united thereto.

5. An electrical device adapted for photograph and other uses requiring high light intensity and consisting of an interchangeable plug comprising an insulating plate carrying terminal connection members, contacts carried by said plate and electrically connected with said terminal connection members, and a refractory metal lament extending across the face of said insulating plate and designed so that upon receiving a very high electric current it is instantaneously vaporized and emits light of high intensity,'said lament having electrical connection with said contacts Without being integrally united thereto.

6. An electrical device adapted for photographic and other uses requiring high light intensity and consisting of an interchangeable plug comprising an insulating plate carrying terminal cony nection members, contacts carried by said plate and electrically connected with said terminal connection members, and a tungsten lament extending across the face of said insulating plate and designed so that upon receiving a very high electric current it is instantaneously vaporized and emits light of high intensity, said` lament having electrical connection with said contacts without being integrally united thereto.

'1. An electrical device adapted for photographic and other uses requiring high light intensity and consisting of an interchangeable plug comprising an insulating plate carrying terminal connection members, a pair of contacts carried by said plate and electrically connected with said terminal connection members, and a lament strung in a plurality of rows across the face of said plate, each of4 said rows being removably connected at one end to one of said contacts so that said rows are electrically connected in multiple, said iilament being designed so that upon receiving avery high electric current it emits light of high intensity. l

- MARCELLO PIRANI. 

